Imaging devices of an electronic camera and so forth provided with an autofocus (AF) function are well known. In this kind of the imaging device, focus adjustment is automatically performed and shooting of a through image (through-image shooting) is commenced by setting a shooting mode. When a release button is pressed halfway in the shooting mode, the focus adjustment is performed. Upon full depression of the release button, taking a regular image for recording (regular shooting) is performed. The regular image is stored in a storage medium of a memory card and so forth.
In the case the focus adjustment is performed when the release button is pressed halfway, there arises a problem in that the regular shooting is not smoothly performed if it takes a time to perform the focus adjustment. In view of this, some of the imaging devices are provided with a focus adjustment mode referred to as a continuous AF mode wherein the focus adjustment is repeated during the shooting mode regardless of the operation of the release button (see Japanese Patent Laid-Open Publication Nos. 08-75984 and 2003-5024, for instance). Meanwhile, such as described in Japanese Patent Laid-Open Publication No. 2003-295039, some of the imaging devices are capable of changing the continuous AF mode and a single AF mode wherein the focus adjustment is performed in response to an input operation (half press of the release button and so forth) instructing the focus adjustment.
In the continuous AF mode, since the focus adjustment is repeated, it is possible to smoothly perform the regular shooting. However, there is a problem that power consumption increases in comparison with the single AF mode.